Electromagnetic switch.



f ZZZeSS/@S/ Tl E. BARNUM. ELEGTROMAGNETIG SWITCH. APPLICATION FILED JULY 5, 190e.

905,782. Patented Deo. 1,1908.

2 SHEETS-SHEET 1.

T. E. BARNUM. ELEGTROMAGNETIG SWITCH.

PPLGTINILED JULY 5, 1906. 905,782. Patented Deo. 1, 1908.

2 SHEETS-SHEET Z.

UNITED sTATEs PATENT onnron.

THOMAS E. BARNUM, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO CUTIlE-HAMMER MANU- lFACTURIN G COMPANYOF MILWAUKEE', WISCONSIN, A CORPORATION OF WISCONSIN.

ELECTROMAGNETIC SWITCH.

Patented Dec. 1, 1.908.

Original application led April 15, 1905, Serial N o. 255,713.A Divided and this application led July o,- 1906.

Serial N o. 324,812.

To' all whom it may concern:

Be it knownthat I, THOMAS E. BARNUM, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented new and useful Improvements in Electromagnetic Switches, of which the following is a full, clear, concise, and exact description, reference being had to the accom anymg drawing, forming apart of this specidJcation.

My invention relates to improvements in magnets for use on alternating current circuits, my object being to provide a magnet which will be simple in construction, and at the same time self-protecting from over-heating after the magnet has attracted its armature.

My invention provides a pulling magnet in which, when the current` is iirst admitted to the windings thereof, a large amount of current will iiow and, consequently, exert a strong pull on the armature, but'after the armature has been attracted to the coil, the amount of current iiowing through the'coil is greatly reduced. A

A still further object of my invention is to provide means .for connecting the armature of the magnet to a switch, whereby a hammer blow will be given in o ening and closing the switch to more rea ily operate the same.

I lhave illustrated the. preferred embodi ment of my invention in the accompanying drawings, in which:

Figure 1 is a front elevation of my device showing the same operating a switch; Fig. 2

is a side elevation of the s ame Fig. 3 is a bottom plan view of my device; Fig. 4 is a front elevation of a modification of my device Fig. 5 is a side elevation thereof and Fig. 6 is a bottom view.

In one forni of the practical embodiment of my invention, upon a suitable base 1, made of. insulating material, usually in the form of a marble slab, is mounted a solenoid winding 2 of the usual type, which is sur roundedv by and vsupported within an iron shroud 3 having projecting lugs 4, through which screws are passed to secure the same to the base 1. Suitable screws 5 pass through the lower side of the shroud to adjustably support the coil upon the same. The shroud 3, it will lbe noted, is not continuous and on its underside is cut away to form the air space 6. A core or plunger 7 is adapted to 55 oplerate in the coil and be raised thereby W en the current is admitted to the windings of the coil.

The iixed air gap 6 between the sides of the plunger and the sides of the frame is so pro- 50 ortioned in relation tol the variable air gap etween the to of the lunger and the top ofthe frame, w en the p unger is down, that the self-inductance of the magnet will be. suiiieiently small to ermit enough current to flow-.to fully energlze the magnet so as to close theswitch, but not so small as to allow an excessive current to flow. The fixed airv gap is also so proportioned that when the plunger is'up, and consequently the variable 70' bifurcations 11 of a contact plate and be held in a closed position thereby. In order that this plate may' be mounted in line with the .louter end of the switch-arm,l it is preferably .i

secured by means of a screw 12 upon the outer end lof a pin 13 projecting from the base. The screw 12 passes through the pin and a nut 14 upon the upper end thereof -holds in positiona spring 15, which` extends below the lower ends of contact clips 11, so that the circuit is broken at this point last and the s ring takes the arc resulting from o ening tlxie switch with the current passing. T ie downward movement of the switch-arm is limited by a stop 16 secured upon thc' base 1.

The central portion of the switch-arm is enlarged and has formed therein a slot 17, through which is adapted to pass a rod 18 secured at its upper end to the core or 10o lunger 7. A nut 19 is screwed upon the lbwer end of the rod and is ada ted, whenthe rod is raised by the core or pfiinger 7, to engage the switch-arm and move the same. A sot-nut 20 is' also provided upon the lower 105 end of the rod to prevent the nut19 from being displaced after it has once been adjusted.

in operation, assuming the switeh to be i v o en Wnenthe euri-ent has been admitted to y t e windings oi 'the eoii the seit-induction set up bythqe Wires oi the inagnetizeo. coil is so smaii, dus to the gap in the magnetic oircoi't and to the externa-i air gaps it?, that a iargfe anionnt oi' current Wiii dow through the een and exert a strong poli upon the core to raise. the same. is the i@ xviii not en gage the switeharrn nntiiaiter the core has eeenv started inl its upward mmfeinent, a ha'nannerH bioW Wiii be deiiered to the sWiteii-arm and the saine wiii be readiiy raised by the core or plunger untii'the arnr vnaties Contact Witblthe contact piate il and is engaged' by the spring i5.' As the core is sucked up into the eoii,l the air gap in the magnetic circuit Wiii be decreased and the seiiinduotion set up by the eoiis aeeordingir increased. 'iihen the eore 'has reached its uppermost position, the magnet circuit is so neariy ciosed that the self-indiietion-is so great that the amount of ourent iiowing Y heid in. nosition.

through the eoii is redueed to just enough to own oore in a raised position.

tire switoh is to be opened oy eut-- oni7` the ein-rent through the cori, the

Wiii be 'oerinitted to drop by its oww. Weight and noon the sWitoh-arni, releasing the saine ain?. di to s ioef'erniost posit in, to o, i have shovn a s ht devies, which insniating :2i secured at right angles 'to the base and maintained in position by ,l g tnrougn the piate and oi the mag iron shroud o form-s a support for 'the oonpassing through said ooniieid position' by nuts i., is aise supported and by the boit i dependr be spring.

d to said piate u r* a 1. ffi Y. nits 2.1 and to toe ioafei ing supo-ort l o aina This appiieation is a division of piioation Seriai No. 2553?@ iorii i5, .i905 for current N T f this oesoribed my invention desire seizurev by deiiver a fhaininer biow` member, a switch-arm soap/sa ocre therefor, a pivoted'sWitoh-arm, means for olierativeiy connecting said core and said switch-arm: in such 'manner that'a hammer blow is struck u on the switch-arm when energization or energization of the switch takes piace, a contact'adapted to be engaged bythe free end oi said switch-arm, and spring for en'gaglng said free end of said sivitoii-arni to retain the saine in engag/ement with saidoontaot.

2. The. combination with a solenoid, of a core therefor, 'a pivoted switch-arm, means for operatively connecting said core and said switch-arm in such ina-nner that a hamnier blow is struck upon the switch-arm When -energization lor denergization of the switch takes piaee, contact mechanism/for engagement' by said switch-arm, and .spring :mechanism for association with said'oontact mechanism and the free end of said switcha-rin for retaining said switch-arm in such engagement. l1

' 3. The combination with asoienoid, ofa Core therefor, a pivoted switch-arm operaf tiveiyconneoted with said core in such :maw

ner that a hammer bioW is struc'k upon switoh-arni when enorgization or dene'rgi.n zation of the switch. takes piace, Contact mechanism for engagement by said sw-itoitI arin, Aai'id spring mechanism for association Wit i said contaot 'mechanism and the free end oi said switch-arm for retaining said switoherni in 'such engagement.

4. The combination of a .main supporting member, a switohearrn ivoted upon said supporting member and i airing an opening therein, a eontact, carried said supoorting member 'ier engagement by the Ifree end oi' said `s *karin/, spring means associated with ,aid Contact ier tain i said switcharm in engagement Wim solenoid magnet mounted open porting ineinbe, a core for sait magnet, a reduced'etension Aiones 'passing through openin oi.' sait. arin, and means on said reduced extension ior engaging said switch-arm upon energization oi the magnet.

supporting member and aving an opening theein, a Contact, carried by said supporting member, for engagement by the free end of said switch-arin, spring means associated with said Contact for retaining said switchine combination of a main supporting ivoted upon said lli arm in engagement with said Contact, an iron.

shroud mounted upon said supporting'inembei", a soinioid magnet disposed Within said shroud, a oore fos said ,solenoid magnet, a reduced extension 'for said eore passin throngh the opening oi said switch-arm, an

means on said reduced extension orengagswitch-asin upon eneigization or tno magnet.

o. The eombination oi a supporting member, an iron shroud mounted upon said supporting member, a solenoid magnet disposedvithin said shroud, a corefor said solen| oid magnet, a switch-arm pivoted upon said supporting member having an opening therein, a reduced extension for said core extending through the openingof said switch-arm, means on said reduced extension for engaging said switch-arm upon energization and deenergization of the magnet, a contact for engagement by the free end of said switch-arm mounted upon said supporting member, and spring means associated With said contact for retaining the said switch-arm in engagement with said contact.

7. The combination of a main sup orting member, two pins projecting thereflfom, a switch-arm pivoted upon one of said pins and having anaperture therein, a contact for engagement by the free end of said switch-arm mounted on the second of said pins, spring means associated With said contact for retaining said sWitch-arm in engagement With said contact, aniron shroud mounted upon said supporting member, a solenoid magnet disposed Within said shroud, a core for said solenoid magnet dis osed substantially in the plane of the tops o' said pins, a reduced extension for said core passing through the opening of said switch-arm, and meanson 'said reduced extension for engaging said sWitch-armupon energization and denergization of the magnet.

8.- The combination of a main supporting member, a `switch-arm ivoted upon said supporting member and havin an opening therein and having its free eng flattened, a

forked contact member for receiving the fiattened end of said switch-arm, sprmg'means passing through the opening y duced extension for engaging said switcharm upon energizati'on and denergization of the magnet. I

9. The combination of a main supportin member, a switch-arm ivoted upon saidv supporting member and avin an opening therein and having its free en 4iiattened, a forked contact member for receiving the iiattened end of said switch-arm, spring means associated with said contact for retaining the iiattened end of said switch-arm in the forked' contact membeiyan iron shroud mounted upon said `supporting member, a solenoid magnet dis osed Within said shroud, .a core for said so enoidfmagnet, a reduced extension for said core passing through the-opening of said switch-arm, and means on said reduced extension for striking a hammer blow on said switch-arm upon energizationv and denergization of the magnet.

In Witness. whereof, I have hereunto subscribed my name in the presence of two witnesses.

THOMAS E. BARNUM. Witnesses: f

OSCAR A. KELLER, A. H. BARNICKEL. 

